Copper can have a shiny, warm, new-penny hue, and it also looks amazing oxidized. It will tarnish, and for some people it turns your skin green. I have had less problem with this on my chainmaille copper rings than I do for copper wire bracelets, for example, but it does depend on your skin pH. Some say that means it's doing its job. For more about the properties and possible health benefits of copper, visit the Materials page.